What indicates a yellow alert in airport operations?

A yellow alert in airport operations specifically indicates that lightning has been detected within ten miles of the airport. This status is crucial for ensuring the safety of personnel and passengers as it serves as a cautionary measure to prepare for potential impacts on airport operations. When lightning is within this proximity, there could be a risk of strikes that endanger ground crew activities, boarding procedures, and overall air traffic safety.

Understanding this criterion is essential for airport personnel who must remain vigilant and responsive to weather conditions that can affect operations. A yellow alert leads to specific safety protocols being enacted, such as suspending outdoor activities, clearing personnel from the ramp, and monitoring weather updates closely.

In contrast, other choices relate to weather conditions that might pose risks but do not trigger the same level of alert as lightning within ten miles. For instance, while gusty winds and low visibility can certainly affect airport operations, they do not specifically meet the criteria for a yellow alert, making the definition of the yellow alert primarily centered on lightning detection.